The description of your zucchini leaves makes me think of bacterial canker or some other bacterial disease. A fairly safe prevention of bacterial infections is Bordeaux mixture. A fairly safe treatment for bacterial infections on plants is 1 part iodine tincture mixed with 10 parts water sprayed onto the plants 2-3x per day until symptoms are resolved. You may find that that cultivar of zucchini just isn't suited for your region. Squash are extremely variable in disease resistance and growth habits between cultivars. What grows well for someone in one area may not be the best cultivar in another area. You may want to try growing a different cultivar next year.

thanks for the info, nick